Process for dyeing hydrophobic textile material

ABSTRACT

IN A PROCESS FOR DYEING TEXTILE MATERIAL MADE FROM HYDROPHOBIC SYNTHETIC POLYMERS CONTAINING POLAR GROUPS, WHEREIN DYEING IS CARRIED OUT IN A HOMOGENOUS SOLUTION OF A DYESTUFF OR MIXTURE OF DYESTUFFS IN AN ORGANIC SOLVENT OR SOLVENT MIXTURE, AN IMPROVEMENT IS DISCLOSED WHICH COMPRISES DILUTING THE DYEBATH, EITHER CONTINUOUSLY OR IN PORTIONS, DURING SAID DYEING PROCESS WITH A SECOND SOLVENT OR WITH WATER WHICH MAY CONTAIN A MAXIMUM OF 30% OF ORGANIC OR INORGANIC IMPURITIES, WITHOUT PRECIPITATING THE DYESTUFF, SAID SECOND SOLVENT OR WATER BEING MISCIBLE WITH THE FIRST ORGANIC SOLVENT, SAID PROCESS BEING CHARACTERIZED BY IMPROVED DYEINGS.

Unneaseres Patent US. Cl. 8-172 20 Claims ABSTRACT OF THE DISCLOSURE In a process for dyeing textile material made from hydrophobic synthetic polymers containing polar groups, wherein dyeing is carried out in a homogeneous solution of a dyestuff or mixture of dyestuffs in an organic solvent or solvent mixture, an improvement is disclosed which comprises diluting the dyebath, either continuously or in portions, during said dyeing process with a second solvent or with water which may contain a maximum of 30% of organic or inorganic impurities, Without precipitating the dyestulf, said second solvent or water being miscible with the first organic solvent, said process being characterized by improved dyeings.

This application is a continuation-in-part of our pending application, Ser. No. 762,143, filed Sept. 24, 1968, now abandoned.

The present invention relates to a process for dyeing hydrophobic staple fibres, filaments and yarns and knitted and woven fabrics made therefrom, or blends thereof with other fibre materials.

The invention provides a process for dyeing textile material made from hydrophobic synthetic polymers which contain polar groups, wherein dyeing is carried out in a homogeneous solution of a dyestuif or mixture of dyestuffs in at organic solvent, preferably at the boiliig point of the dyebath and, during dyeing the dyebath is diluted either continuously or in portions with a second solvent or with water, said second solvent or water being miscible with the first organic solvent. Water is preferred as diluting agent. It may be applied in any form, for example as normal tap water or a steam, and it may contain organic or inorganic impurities such as are found'in clarified sewage, hard water or seawater in amounts up to a maximum of 30% by weight. It has been found that this successive dilution of the dyebath during the dyeing process favorably shifts the dyeing equilibrium and affords dyeings of superior quality when compared with similar dyeings without the slow dilution according to the instant invention.

The process may be used for dyeing man-made fibres which are hydrophobic in character, for example, cellulose triacetate and secondary acetate fibres, and especially synthetic fibres, for example, linear polyester fibres made, for example, from terephthalate acid and ethylene glycol or 1,4-dimethylolcyclohexane and copolymers made from terephthalate acid and isophthalic acid and ethylene glycol, acrylic or acrylonitrile fibres, for example, polyacrylonitrile fibres and copolymers made from acrylonitrile and other vinyl compounds, for example, acrylic esters, acrylic amides, vinylpyridine, vinyl chloride or vinylidene chloride, copolymers made from dicyanoethylene and vinyl acetate and from acrylonitrile block copolymers, fibres made from polyurethane and fibres made from polyamides, for example, nylon 6, nylon 6, 6, nylon 11 and nylon 6, 10. Blends of these fibres with cellulose or natural polyamide fibre materials can also be used.

The process is preferably applied to cellulose acetate, polyester or synthetic polyamide material in the normal or texturized state.

It is preferable in the dyeing of polyester fibre material to use solvents that have a boiling point of at least C., dyeing being carried out at a temperature of at least 100 C., that is to say primarily atthe boiling point of the dyebath but below 150 C. When dyeing synthetic polyamide and cellulose triacetate fibre materials, solvents having a lower boiling point are also suitable. The boiling point of the solvent mixture must be so chosen that the fibre is not degraded.

Solvents which are suitable for use as the first solvent in the process according to the invention may be divided into two groups, namely (1) hydrophilic solvents which are miscible with water and (2) hydrophobic solvents which are sparingly miscible or virtually immiscible with water.

When a hydrophobic organic solvent or a solvent that is partially miscible with water is used as first solvent it is advantageous to use a second solvent which has poorer solvent power or no solvent power for the dyestuif as diluting agent. Suitable hydrophobic organic solvents are, for example, aliphatic and aromatic hydrocarbons such as kerosene and naphthalene, and halogenated in particular, chlorinated aliphatic hydrocarbons such as trichloroethylene, tetrachloroethylene (Perchloroethylene), or 1,1,1-trichloroethane. It is also possible to use a solvent mixture as first solvent in the process of the present invention.

When water the preferred diluent, is used, the hydrophilic solvents of group (1) are suitable as first solvent. These hydrophilic solvents of group (1) may be divided into three preferred sub-groups, namely (a) solvents which are only partially miscible with Water, (b) solvents which are miscible with water in all proportions, and (c) acidic organic solvents, especially low-molecular-weight fatty acids. Lower as used in this text and the appended claims in connection with an aliphatic radical means that said radical has a maximum of four carbon atoms.

Hydrophilic solvents miscible with water are, for example, monovalent lower aliphatic alcohols such as lower alkanols, e.g. methanol, ethanol, isopropanol, or n-butan01; divalent aliphatic alcohols such as ethylene glycol; or polyvalent alcohols such as glycerol; and higher boiling glycol derivatives such as alkylene glycol alkyl ethers and thioethers, e.g. ethylene glycol monomethyl, monoethyl or monobutyl ether, and diethylene glycol monorn'ethyl or monoethyl ether, and thiodiglycol; and polyethylene glycols, in so far as they are liquid at room temperature; lower cyclic ethers, e.g. diodxane, tetrahydrofuran; ketones and lactones such acetone, acetyl acetone, diacetone alcohol, 'y-butyrolactone; acetates, e.g. ethyl acetate; acetonitrile; ethylene carbonate; pyridine; and the group of water-miscible active solvents boiling above C., for example N,N-dialkylamides of lower monocarboxylic acids such as N,N-dimethylformamide, N,N-dimethylacetamide; bis-(dimethylamido)-methane-phosphate, tris-(dimethylamido)-phosphate, N-methylpyrrolidone, 1,5-dimethylpyrrolidone, N,N dimethylmethoxyacetamide; amides of carbonic acid such as N,N,N',N'-tetramehylurea; tetramethylene sulphone (sulpholane), S-inethylsulpholane and dimethyl sulphoxide.

When the solvents contain sulfur atoms, these atoms are preferably divalent or haxavalent.

Naturally, those solvents which do not damage the fibre are chosen for use in accordance with the invention. Bulletin No. X-156, pages 14-15, 1962 edition issued by E. I. du Pont de Nemours and Company is a suitable guide tofibre/ solvent compatibility. Compatibility may also be determined by a small-scale test.

Solvent Diluting agent Water, sodium chloride solution, sodium chloride solution and subsequent Acetic acid, propionic acid,

ethoxyacctic acid, ethylene glycol, propylene glycol,

butyl Cellosolvc, Collosolvc, and addition of water (ratio by dioxane, glycerol, formic acid, Volume 1:1), calcium chloor acetylacetone. ride solution (10%) or 10% urea solution. and Acetic acid, propionic acid, or and {10% sodium hydroxide formic acid. solution.

or Benzyl alcohol, or a mixture of and perchloroethylene and N,N- n-heptane.

dimethylformamide.

The dyestuffs to be used in accordance with the invention are preferably members of the well-known class of water-insoluble dyestuffs, for example, monoazo, disazo and polyazo dyestuffs, and dyestuffs of the anthraquinone, naphthoperinone, quinophthalone, oxazine, phthalocyanine and methine series, including styryl, azamethine and azostyryl dyestuffs and also soluble metal-complex dyestuffs of the azo and formazan series.

However, other suitable kinds of dyestufi may also be used, for example, vat dyestuffs, provided they are soluble in the above-mentioned solvents.

The dyestuffs usable according to the present invention are known and are produced by known methods, such as are given, for example, in the Color Index of The Society of Dyers and Colourists, Bradford, Yorkshire, England, and The American Association of Textile Chemists and Colorists, Lowell, Mass.

The amount of dyestuff employed depends on the desired depth of shade, but is usually in the range of from 0.01 to 10% of the weight of the fiber material.

An advantage of the dyeing process of the invention as compared with conventional dyeing processes is that the dyestuffs used do not require special preparation. When dyeing is carried out according to a conventional process using an aqueous liquor, the dyestufi' has to be used in the form of a special preparation to ensure easy dispersion in the water.

The process of the present invention is preferably carried out without the addition of a dispersing agent. An advantage ensuing therefrom is that the dyed textile material is easier to clean. However, surface-active agents may be added to the dyebath if desired or required.

Suitable mixtures with surface-active agents are mentioned in German patent specification No. 1,261,613.

During the dyeing process, the material being dyed may be present in the form of loose staple, non-woven material, yarn, or knitted or woven fabric. Dyeing is carried out in a bath, especially on a jig, winch or cheesedyeing machine or some other similar machine suitable for the nature of the goods to be dye, the material being either in the form of loose fibres or in another form obtained by mechanical processing. If blended fabrics are used, the synthetic fibres and the natural fibres may be dyed together in one dyebath according to the present invention, appropriate dyestufi for the natural fibre being added to the dyebath, or the blended fabric may be dyed in two separate steps, dyeing the natural fibres according to conventional methods.

Dyeing may be carried out in dyeing machines or vessels which are in contact with the ambient atmosphere (if necessary, through a reflux condenser) or in closed vessels, for example, pressurized vessels, with or without the application of excess pressure.

It is expedient to feed the diluting agent into the dyebath in a manner such that the dyestuif present in the bath is not precipitated. The gradual addition of the diluting agent causes the dyestuif to draw onto the fibre material.

The quantitative ratio of solvent to diluting agent may vary within wide limits. It is advantageous to use a volumetric ratio greater than 1:1, that is to say, more diluting agent than solvent. The maximum rate of addition depends on the speed of the dyeing process and is preferably such that the dyestulf is always just in solution. In case the water is added as steam, the rate of addition can be increased considerably. The initial addition is usually slower and can increase in velocity with increasing exhaustion of the dyebath. The dyestutf concentration in the initial bath depends upon the desired shade and can be, for example, between and 1 and grams, preferably 2.5 to 50 grams per kilogram of fibre material.

Part of the solvent may be removed from the dyebath during the dyeing process by steam distillation or by azeotrope, distillation. In this manner an increase in the total volume of the dyebath may be avoided or the amount of dyebath may be kept at a minimum, thus requiring less dilution.

When the required depth of shade has been obtained, the material is removed from the dyebath, rinsed if necessary or given another after-treatment such as alkaline reduction, cleaning with acetone and/or soaping. The material may also be treated with steam or a current of hot air to remove any solvent still adhering to it.

The process is preferably used for piece dyeing, however, material in other forms, such as loose silver yarn, may also be used.

The following non-limitative examples illustrate the invention. Unless otherwise stated, the parts are given by weight and temperatures are given in degrees centigrade.

EXAMPLE 1 2.5 parts of the dyestuff of the formula E; @nQN H l.

are dissolved in 1,000 parts by volume of ethylene glycol ethylether. 100 parts of a polyethylene glycol terephthalate (polyester) staple fibre fabric are introduced into the dyebath and dyeing is carried out under reflux for two hours. During the first hour 1,000 parts by volume of water are added gradually according to the time table given below. After the dyeing is completed, the samples are washed, reduced with a solution of sodium hydrosulfite and caustic soda, acetone cleared, soaped and dried. A deep level yellow dyeing is obtained.

Similarly good results are obtained when the polyester staple fibre fabric is replaced by a polyester filament fabric.

Dilution time table Amount of diluent Time of addition added (in parts EXAMPLES 2-5 The procedure of Example 1 was repeated, but using one of the following diluting agents in place of water: Example Diluting agent 2 aqueous sodium chloride solution.

3 10% aqueous calcium calcium chloride solution. 4 10% aqueous sodium sulphate solution. 5 10% aqueous urea solution.

EXAMPLE 6 2.5 parts of the dyestutf given in Example 1 are dissolved in 1,000 parts of ethylene glycol. 100 parts of water are added to the dyebath. Then 100 parts of a polyester staple fibre fabric are introduced into the dyebath and dyeing is carried out for two hours on an oil bath (bath temperature 140 C.) under reflux. During the first hour dilution is carried out according to the time table given below. After dyeing is completed, the fabric is finished in the manner given in Example 1. A deep, level yellow dyeing is obtained.

Similarly good results are obtained when the polyester staple fibre fabric is replaced by a polyester filament fabric.

Dilution time table Amount of diluent Time of addition added (in parts If the dilution is discontinued after minutes, instead of being carried out for a full hour as given above, a level yellow dyeing is obtained, the shade of which is not quite as deep as that obtained after diluting for the whole time.

EXAMPLE 7 2.5 parts of the dyestuff of the formula are dissolved in 1,000 parts of ethylene glycol. parts of nylon 6 fibre material are introduced into the dyebath and dyeing is carried out at 100 C. on a water bath for 2 hours. During the first hour 1,000 parts of water are added as diluting agent in the manner described in Example 1. After the dyeing is completed, the material is removed from the dyebath and rinsed with hot and then cold water and dried. A deep, level brown dyeing is obtained.

Similarly good results are obtained when the nylon 6 fibre material is replaced by a fabric of nylon 66 fibre material or of cellulose triacetate fibre material and other wise following the above procedure.

EXAMPLE 8 2.5 parts of the dyestuif mixture of the formulas HO 0 NHCHa 0H 0 NHCH;

and

are dissolved in 1,000 parts of propanediol. 50 parts of nylon 6 fibre material are introduced into the dyebath and dyeing is carried out on a water bath as described in Example 7. A deep, level blue dyeing is obtained.

Similarly good results are obtained using nylon 66 or cellulose triacetate fibre material.

EXAMPLE 9 A mixture of 0.23 part of the dyestuif of the formula and 0.11 part of the dyestulf of the formula EXAMPLE 10 2.5 parts of the dyestufi of the formula h) NH;

OOHa

N HS 02 CH:

are dissolved in 1,000 parts of glacial acetic acid. 50 parts of polyester fabric are introduced into the dyebath and dyeing is carried out as described in Example 1, adding 1,000 parts of water during the first hour.

A brilliant, deep pink dyeing is obtained.

EXAMPLE 11 2.5 parts of the dyestutf of the formula 0 5111-0 O-NH are dissolved in 1,000 parts by volume of n-butanol. 50 parts of polyester fabric are introduced into the dyebath and dyeing is carried out as described in Example 1, adding 1,000 parts by volume of water during the first hour. A brilliant yellow dyeing is obtained.

EXAMPLE 12 2.5 parts of the dyestulf of the formula NHQ are dissolved in 1,000 parts by volume of acetyl acetone. 50 parts of polyester fabric are introduced into the dyebath and dyeing is carried out as described in Example 1,

7 adding 1,000 parts of water during the first hour. A deep, level blue dyeing is obtained. I

EXAMPLE 13 2.5 parts of the dyestuff of the formula H N i) EXAMPLE l4 2 parts of the dyestulf of the formula N0, OH

are dissolved in 200 parts by volume of benzyl alcohol. 40 parts of polyester staple fibre yarn are introduced into the dyebath and dyeing is carried out at 100 for an hour. During this time, 800 parts by volume of n-heptane are added gradually in the manner described in the earlier examples. After the addition is over, the material is removed from the dyebath, squeezed, washed in cold perchloroethylene and acetone, and dried. A deep level blue dyeing is obtained.

When dyeing is carried out without the slow addition of the diluent, the yarn is dyed only to a weak shade.

EXAMPLE 15 0.4 part of the dyestulf of the formula I HO OH is dissolved in 300 parts of perchloroethylene and parts of N,N-dimethyl formamide at 121. The temperature is lowered to 108 and 40 parts of polyester staple fibre yarn are introduced into the dyebath and dyeing is carried out at the same temperature for 2 hours. After the first hour of dyeing, 800 parts by volume of n-heptane are added gradually in the manner described in the earlier examples. After the dyeing is completed the, samples are washed in cold perchloroethylene, acetone, water and dried. A deep level orange-brown dyeing is obtained.

When the dyeing is carried out by adding the diluent n-heptane at the beginning of the dyeing, the yarn is dyed only to a weak shade.

EXAMPLE 16 100 parts of polyester fabric are heated under reflux in a solution of 3 parts of the dyestulf of the formula i) NH:

in about 1,000 parts of ethylene glycol/water (3:2 parts by volume). 4,000 parts by volume of water are added slowly until the goods-to-liquor ratio is 1:50. The fabric is removed from the dyebath, rinsed with cold acetone and dried. A blue dyeing displaying a good degree of levelness is obtained.

A blue dyeing displaying a good degree of levelness is also obtained when the polyester fabric is replacedby a cellulose triacetate fabric or a fabric made from filament nylon 6,6 or a texturized nylon 6,6 fabric, and rinsed with hot and cold water instead of with cold acetone.

EXAMPLE 17 parts of polyester fabric are heated under reflux in a solution of a dyestuff mixture comprising 1.4 parts of the dyestulf of the formula and 0.6 part of the dyestuif of the formula in 1,000 parts of acetic acid. 4,000 parts of water are added within 60 minutes, the goods-to-liquor ratio being 1:50. An orange dyeing is obtained. H

EXAMPLE 18 10 parts of a nylon 6,6 fabric are heated under reflux in a solution of 1 part of the 1:2-chromium complex of the dyestutf of the formula V COOH in 100 parts by volume of ethylene glycol, and 300 parts of water are slowly added. A yellow dyeing possessing a good degree of levelness'and a good depth of shade is obtained.

A dyeing displaying an equally good degree of levelness and depth of shade may be obtained when the substratum used is a tricot fabric made from texturized nylon 6,6. EXAMPLE 19- A similar orange dyeing may be obtained by replacing the dyestuff indicated in Example 3 with the chromium: complex of the dyestulf of the formula EXAMPLES 20-22 By dyeing texturized tricot fabric made from nylon 6,6 with the dyestuffs listed in Column I of the following table according to the procedure described in Example 3, deep, level dyeings may also be obtained, the shades being listed in Column II.

Ex. I I! 20 Cobalt complex of a mixture of the dyestuffs of the tormulas Brown.

0H OH OH zen-Q N=N-c-c-cm and g [I U H0-- /N I N 0 E S 0 I H; la la H lmofl Cl 21 1:2 cobalt complex 01 the dyestufl o! the formula Violet.

22..-..-.. 1:2-chromlum complex or the dyestufl o! the formula Orange;

OgNH-CH:

23 Cobalt complex of: mixture of the dyestuffs o! the Iormulu Brown.-

OH OH OH =N d N=N--c- :-cm

an RN no-5 l A N S 0 0 0 a a I (311; NE. NH H; JIIHIOCHI 24.....:. 1:2chromlum complex 0! the dyestufl of the (ormula Orlnze.

70 1-amino-4-hydroxy-5-para-tolylsulphonylaminoanthraquinone, 1,S-dihydroxy-5,8-dibenzylaminoanthraqfinone, 1-amino-2-phenoxy-5-para-tolylsulphonylaminw 1,4-diamino-2,3-dichloro-S-nitroanthraquinone, anthraquinone, 1,4-diamino-2,3-dibromo-S-nitroanthraquinone, 7. l-stearylamino-S-benzylaminoanthraquinone and the The following dyestuffs may be used in the preceeding examples to obtain similar results:

dyestuffs of the formulas o=crrmomomooo-cna NC C=CH NH-CO-CHa We claim:

1. In a process for dyeing textile material made from hydrophobic synthetic polymers contalning polar groups, wherein dyeing is carried out in a homogeneous solution of a dyestulf or mixture of dyestuffs in a first orgamc solvent, or solvent mixture, the improvement thereln which comprises diluting the dyebath, either continuously or n portions, during said dyeing process with a second organic solvent which has poorer solvent power than the first organic solvent for the dyestulf or with water which may contain a maximum of 30% of organic or inorgamc 1mpurities, without precipitating the dyestuff, said second organic solvent or water being miscible with the first organic solvent.

2. A process as claimed in claim 1, wherein dyeing 18 carried out at the boiling-point of the dyebath, but below 150 C.

3. A process as claimed in claim 1, wherein the diluting agent used in water.

4. A process as claimed in claim 3, wherein an organic solvent miscible in any proportion with water is diluted with water.

5. A process as claimed in claim 4, wherein the organic solvent is selected from a lower fatty acid, an alcohol, a higher boiling glycol derivative, a polyethylene glycol 14 which is liquid at room temperature, a lower cyclic ether, a ketone, a lactone, acetonitrile, ethylene carbonate, pyridine and a solvent from the group of Water-miscible active solvents boiling above 120 C.

6. A process as claimed in claim 1, wherein the diluting agent is a second organic solvent which has poorer solvent power or no solvent power for the dyestuff.

7. A process as claimed in claim 6, wherein the first organic solvent is selected from a hydrophobic solvent or a solvent that is partially miscible with water.

8. A process as claimed in claim 7, wherein the first organic solvent is chlorinated hydrocarbon.

9. A process as claimed in claim 7, wherein the first organic solvent is benzyl alcohol and the diluting agent is n-heptane.

10. A process as claimed in claim 1, wherein the dyestuff is dissolved in a solvent mixture.

11. A process as claimed in claim 10, wherein the solvent mixture consists of a chlorinated aliphatic hydrocarbon and a dialkyl amide of a lower fatty acid.

12. A process as claimed in claim 11, wherein the solvent mixture consists of tetrachloroethylene and N,N- dimethyl formamide and the diluting agent is n-heptane.

13. A process as claimed in claim 4, wherein a disperse dyestuff is used.

14. A process as claimed in claim 4, wherein a vat dyestufl soluble in an organic medium is used.

15. A process as claimed in claim 1, wherein textile material based on cellulose triacetate or secondary acetate is dyed.

16. A process as claimed in claim 1, wherein textile material based on linear aromatic polyester is dyed, or a blend thereof with other fibre material.

17. A process as claimed in claim 1, wherein textile material based on a nitrogenous polymer is dyed, or a blend thereof with other fibre material.

18. A process as claimed in claim 17, wherein synthetic polyamide textile material is dyed, or a blend thereof with other fibre material.

19. A process as claimed in claim 16, wherein dyeing is carried out at a temperature of at least C. in an organic solvent having a boiling point of at least 100 C.

20. A process as claimed in claim 18, wherein a metalcomplex dyestulf soluble in an organic medium is used.

References Cited UNITED STATES PATENTS 2,828,180 3/1958 Sertorio 8-174 X 3,120,423 2/1964 Herschler et a1 8--178 3,313,590 4/1967 Delano et al. 8-173 OTHER REFERENCES I. A. 'Leddy, Amer. Dyestuflf Reporter, Apr. 18, 1960, pp. 57-58.

C. B. Stevens et al., JSDC, 72, 1956, p. 100.

T. Vickerstalf, The Physical Chemistry of Dyeing, 1954, pp. 23-24, Publ. Interscience Publishers Inc., N.Y.

K. Venkataraman, The Chemistry of Synthetic Dyes, vol. 1, p. 248 (1952).

LEON D. ROSDOL, Primary Examiner T. J. HERBERT, Jr., Assistant Examiner U.S. Cl. X.R.

8-21 R, 21 B, 21 C, 173, 174

' Umm 5mm; PA'LENT ()FFICE CER'ELH IQATE OF QOREUHUN 3,758,272 Dated September 11, 1973 Keshav V. Datye and Branimir Milicevic Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Claim 3, Column 13, line 60, change "in to is Signed and sealed this 1st day of October 1974.

(SEAL) Attest:

McCOY M. GIBSON JR., 7 Ca MARSHALL DANN Attesting Officer Commissioner of Patents FORM PO-1050 (10- USCOMM-DC scam-ps9 I v u 5.G0vERm-1:NT PIIINTING OFFICE: I959 0-366-334 I 

